Saw-mill dog



' Model.)

W. MQWILKIN.

SAW MILL DOG. No. 294,711.

Patefited Mar. 4, 1 884:

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7% vilmz S ATES ATENT .SAW-MILL' DOG.-

' SPECIFICATION forming part of Letters Patent No. 294,711, dated March4, 1884, i

' Application filed March 21, ISSJ. Renewed January 14, 1S84. No model.)

To all whom it may concern.- I

Be it known that I, WILLIAM M. WILKIN, a citizen of the United States,and a resident of Erie, in the county of Erie and State of Pennsylvania,have invented new and useful Improvements in Saw-Mill Dogs; and Idohereby declare that the following is a full, clear, and exactdescription thereof, reference being had to the accompanying drawingsand the letters or figures of reference marked thereon.

My invention relates to the dogging apparatus of a saw-mill head-block;and it consists in certain improvements or modifications of theconstruction shown in an application for a patent now pending in thePatent Office, of which I am also the inventor. In the apparatus towhich I have just referred, two dogs are arranged so as to grasp the logorcant from opposite directions, and are pivoted together by theirshanks, which are long, and near their bits they are pivoted to bars,which extend back to the back part of the knee, and are there pivotallyattached to the knee. Several modifications were shown in thatapplication; but in all of them the dogs are shown as separate from thebars, which are pivotally connected to the knee near its rear end, whichbars were generally shown and described as spring-bars.

In my present invention the dogs are either firmly connected-to thesebars or an integral part thereof, being forged on the ends thereof.Mypresent invention also contains other minor features, which willappear in the following description.

My device is illustrated in the accompany ing drawings as follows:

Figure 1 is an outline side elevation. Fig. 2 is a front elevation. Fig.3 is a modification of the construction shown in Fig. l.

Ais the base-block on which the knee moves. B is the knee. 0 O are thespring-bars. G O are the dog-bits. D D are the toggle-1evers by whichthe dogs are operated from and toward each other. D is the lever bywhich the toggles are moved. E is the lever by which the doggingapparatus is moved out from or back to the face of the knee. F is aspring connected to the bars 0 O. G is a frame on the side of the knee,for holding the dogging apparatus in place.

The spring-bars in Fig. lare shown as pivoted together at H on the leverE, and have a spring, F, for giving them the effect of springbars. InFig. 3 these bars are shown as forged out of one piece of steel, and soshaped as to be in fact spring-bars.

In Fig. 1 the dog-bits C O are shown as bolted fast to the bars 0 O, andin Fig. 3they are shown as forged upon the ends of the spring-bars. Ideem it preferable to have the dog-bits connected to the spring-bars, asshown in Fig. 1, for the reason that they can be re- -FFICE-.

moved and sharpened with greater facility than when they are a part ofthe spring-bar.

The object in having the dogs- 0 G on the bars 0 0 rather than on thetoggles D D, as in the former case referred to, is that the bits willenter alog of one size at the same angle as a log of a greater or lesssize, while, when they are on the toggles D, they tip in their movementand change their angles, so that on small logs they do not strikefairly, or, if made so as to strike fairly on a small l0g,they would notget a good hold on a big one.

The objects and purposes of the levers D and E are fully set forth inthe said former application, and need not be here repeated. In thisconstruction I provide the lever E witha spring which will keep it back.is shown as a coil-spring, (see 6 in Fig. 1;) but it may be of any form.On the dog 0, I place a stop-pin or lug, c, which comes i'n contact withthe rack or frame G and prevents the dogs being drawn entirely backofthe face of the knee. WVhen the lever E is left free, the spring e willthrow it back, so as to draw the dogs in, and the pin 0 will act as astop to prevent the dogs going in beyond the face of the knee. lVhen theparts are in this position, if

, the toggles are loosened and the dogs allowed to come toward eachother, the spring 6, if undisturbed, will keep the lever E back, andcompel the pin 0 to keep upon the face of the rack G, and hence the dogswill move in a direct line down and up the face of the knee. Thismovement is effected when the dog is being used as a board-dog.

WVhat'I claim as new is 1. In the dogging apparatus of a saw millhead-block, which consists of dog-bits actuated by spring-bars,substantially as shown, to drive them into the log or cant, which Thisspring spring-bars are provided with other proper mechanism forwithdrawing the bits from the log or cant, the said dog-bits formed uponor firmly attached to the outer extremities of said s 'ning-bars, forthe purposes mentioned.

2. In the dogging apparatus of a saw-mill head-block wherein thedog-bits are actuated to enter the log or cant by spring-bars which areattached back of the face of the knee to or connected with a lever, E,by which the said dog-bits can be moved more or less beyond the face ofthe knee, the combination therewith of a spring operating upon said1ever to automatically hold back said dog-bits until the power of saidspring is overcome by power applied to said lever E, and a stop nearsaid dog-bits for preventing the said dog-bits from being drawn backWholly within the face of the knee by the said spring operating uponsaid lever, for the purposes mentioned.

In testimony that I claim the foregoing I have hereunto set my hand this17th day of March, 20

WILLIAM M. WILKIX.

\Vitnesses:

)I. F. HALLEQK, W. S. BROWN.

